As is known, some devices presently used for light signal processing in the integrated optics domain, consist of oxide-based glasses, namely silica (SiO.sub.2), in which optical guides are traced apt to make the light radiation go along a desired path.
The guiding region is generally fabricated by using a method which provides the diffusion of a doping material in the substrate material, or the replacement of the ions initially bonded or merely present as extraneous ions, in order to obtain well-bounded regions where the refractive index will assume particular values.
However, oxide-based glasses have high attenuation values at radiations with wavelengths in the midinfrared region of the electromagnetic spectrum extending from the visible region to about 12 m. This region is presently of high interest, namely in the domain of telecommunications using light signals propagating along optical fibers.
In fact, fibers can be made which have in the midinfrared an attenuation which is so low that very long trunks without intermediate repeaters are possible. Of course, these fibers require at their ends suitable signal processing devices (e.g. integrated optical devices).
Such fibers have been fabricated starting from halide based fibers, namely chlorides and fluorides. Methods of preparing such glasses are widely described in the technical literature. More particularly, a method of producing fluorozir conate glasses is described in U.S. Pat. No. 4,341,873. However, the use of such glasses in integrated-optics devices was not previously described.